Referendum on Political Reform

“A referendum on political reform was held in Slovakia on 18 September 2010, following a successful petition started as a civil activity along with foundation of the classical liberal Freedom and Solidarity (SaS), which later became the third-largest party in the National Council. 401,126 signatures were collected, with 386,000 found valid.
The referendum failed to meet the turnout threshold required under the Constitution of Slovakia, with only 22.8% of the electorate voting: far below the 50% required. Large majorities voted in favour of all six proposals, with between 70% and 95% supporting each proposal.
A turnout of 50% or more was required for the referendum to be valid. Only one referendum in Slovak history has ever crossed this threshold: the 2003 vote on EU membership (51.5% turnout).

References: https://secure.wikimedia.org/wikipedia/en/wiki/Slovak_political_reform_referendum,_2010